Wednesday 6 March 2013 03.04 EST
First published on Wednesday 6 March 2013 03.04 EST

Sweeping changes to the way alleged sex offenders in England and Wales are investigated must be introduced in the wake of the Jimmy Savile scandal and other child exploitation cases, Keir Starmer, the director of public prosecutions, has said.

Urging police and prosecutors to face up to their shortcomings and be more thorough in dealing with child sex abuse, Starmer warned the criminal justice system could not afford "another Savile moment" in five to 10 years.

He also revealed that a national panel would be established to review historic complaints of sex abuse not pursued by police or prosecutors and, if it considered further investigations were necessary, recommend them to chief constables. Starmer told BBC Radio 4's Today programme he expected such cases to be in the hundreds, rather than thousands.

Despite "a lot of good work" in recent years, Starmer said the Savile scandal and so-called "grooming" cases, particularly in the north-west of England, had shown many victims still did not have the confidence to come forward with allegations nor faith in the criminal justice system. There had been an "over-cautious approach" in the past to allegations regarding Savile.

"We need to settle this," Starmer said. "Ten years or so ago, it was thought that police and prosecutors were over-enthusiastic or over-eager in pursuing [such] cases. Now it is thought they are over-cautious. I don't think we can go on like this."

Starmer called for an approach that was fair to innocent suspects but equally fair to victims. The test for bringing a case – whether there is a realistic prospect of bringing a conviction – must not change but the justice system must look more carefully at the way it assessed credibility, he said.

"At the moment, there is a great deal of focus on whether the victim is telling the truth. We need to look equally carefully at the account the suspect is giving, look at the context, look at the pattern of behaviour, make the necessary links and think about how a case can be be built."

Starmer said authorities had to "clear the decks", agree what the approach should be and draft the way cases were investigated and prosecuted to ensure they were fair to both sides. Starmer, who was due to expand upon his themes in a speech in London on Wednesday evening, hoped draft guidelines would be ready by early summer after which there would be three months' consultation on the issue. The final approach would be decided "in reasonably swift order", he said.